The objectives of this study are to: 1) assess the effect of nefazodone on the HPA axis dynamics as measured by cortisol and ACTH at baseline and after a single IV dose of methylprednisolone in normal volunteers; and 2) Investigate the effect of nefazodone on noradrenergic, serotonergic, and platelet parameters in healthy adults in order to gain a preliminary understanding of the effect that nefazodone might have in medically compromised individuals with coronary artery disease or other illness in which adrenergic, serotonergic, or platelet parameters might influence prognosis.